Double drill press



March 15, 1955 G. MEZEY V 2,703,994

DOUBLE DRILL PRESS ATTORNEYS March 15, 1955 MEZEY 2,703,994

DOUBLE DRILL PRESS Filed Aug. 28, 1952 3 Sheets-Sheet 3 INVENTOR Geo gall/e263 ATTORNE Y5.

United States Patent DOUBLE DRILL PRESS George Mezey, Ithaca, N. Y.

Application August 28, 1952, Serial No. 306,887

17 Claims. (Cl. 77-21) This invention relates to a new and improved drill press having one drill for drilling downwardly in a work-piece, and a second drill, aligned with the first, for simultaneously drilling upwardly, the two drills jointly forming a hole through the work-piece. The improved drill press in thus advantageous over the conventional press for such reasons as the following:

1. A hole may be drilled in about half the time;

2. Both ends of the hole will be in perfect alignment;

3. Drill travel is shortened and danger of the drill springing and wandering is reduced to the minimum;

4. Any slight wandering which should occur will cause the misalignment to be present, not at, but between the ends of the hole where it may be easily corrected by the reaming operation which usually follows;

5. The point of break-through at the end of the drilling operation will be between, and not at, the ends of the hole and will require no burring operation, as is necessary when the drill of a conventional drill press breaks through the lower side of the work-piece;

6. Rejections for faulty drilling are almost entirely overcome;

7. Because of Nos. 2, 3, 4 and 6, more accurate estimates may be made of the time expenditure and cost of any job requiring successive drilling of a great number of holes;

8. With elimination of scrap cost of production is decreased to the minimum;

9. Output per man machine hour is increased to the maximum; and

10. Location gauge construction and inspection cost is lowered.

The foremost object of the invention is to provide an improved construction which will be of unusual simplicity yet will be highly efiicient.

Another object of the invention is to provide a construction which will permit easy conversion of even a more or less obsolete drill press to an efiicient doubledrill press, thus conserving and salvaging capital investment in equipment and floor space.

Yet another object of the invention is to provide a novel mechanism whereby conventional downward feeding of the upper drill-carrying spindle will upwardly feed the lower drill.

A further object of the invention is to provide a novel mechanism whereby the lower drill feed will be stopped and this drill lowered out of the way of the upper drill before the two can come together.

A still further object of the invention is to provide a novel mechanism whereby the feed stopping and lower lng means of the lower drill are actuated at the proper time by the descent of the spindle which drives and feeds the upper drill.

Yet another object is to provide for substantially equalizing the wear on the two drills by assigning substantially equal tasks to them.

A still further object of the invention is to provide a mechanism which will assure the same R. P. M. for both the upper and lower drills.

With the above and other objects in view that will became apparent as the nature of the invention is better understood, the same consists in the novel form, combination and arrangement of parts hereinafter more fully described, shown in the accompanying drawings and particularly claimed.

2,703,994 Patented Mar. 15, 1955 In the drawings:

Figure 1 is a front elevation of the improved drill press;

Figure 2 is a side elevation;

Figure 3 is an enlarged fragmentary vertical sectional view on line 33 of Figure 2, partly in elevation, the parts being shown in positions which they occupy at the start of the lowering of the upper drill and the simultaneous raising of the lower drill;

Figure 4 is an enlarged vertical sectional view, partly in elevation, on line 44 of Figure 3;

Figure 5 is a fragmentary view similar to a portion of Figure 6 but showing the coupling dogs released to discontinue the ascent of the lower drill;

Figure 6 is a vertical sectional view on line 66 of Figure 5, showing the parts in readiness for lowering the lower drill as the upper drill continues downwardly;

Figure 7 is an enlarged fragmentary vertical sectional view, partly in elevation, on line 7 -7 of Figure 1, showing the mounting means for the lower drill;

Figures 8, 9, l0, and 11 are operational diagrams;

Figure 12 is a side elevation of one of the coupling dog releasing collars; and

Figure 13 is a plan view of the yoke lever.

The construction shown in the drawings will be rather specifically described but variations may be made within the scope of the invention as claimed.

A standard 15 rises rigidly from a base 16 and is provided with an upper bearing 17 for a drill-driving spindle 18. This spindle 18 extends rotatably through the usual feed sleeve 19 and is so connected with this sleeve that raising and lowering of said sleeve will raise and lower said spindle. The sleeve 19 extends slidably and nonrotatably through a bearing 20 on an arm 21 which is vertically adjustable at 21 on the standard 15. The usual means is provided for raising and lowering the sleeve 19, and this means includes the rotatable operating handle 22. The lower end of the spindle 18 carries a drill 23 in the customary manner.

A table 24 is adjustably mounted upon the standard 15 in a conventional manner and the rear portion of said table is provided with a vertical guide bearing 25 in front of said standard. A vertical shank 26 extends slidably and non-rotatably through the bearing 25 and is provided at its lower end with a forwardly projecting arm 27, the front end of said arm having a vertical bearing 28 in vertical alignment with the spindle 18." A lower spindle 29 is rotatably mounted in the bearing 28 and is suitably held against sliding therein, for example, by collars 30 and 31. The spindle 29 carries a lower drill 32 and the table 24 is provided with a bushing 32 for this lower drill.

A short horizontal shaft 33 is mounted in a bearing 34 secured to the arm 27 and the front end of said shaft 33 is connected by bevel gearing 35 with the lower end of the spindle 29. A flexible shaft 36 connects the rear end of the shaft 33 with the upper end of the upper spindle 18 whereby driving of said spindle 18 by conventional means 37 to drive the upper drill 23 will also effect driving of the lower spindle 29 to drive the lower drill 32 at the same speed.

A yoke lever 37 is fulcrumed centrally between its ends at 38 to the lower end of a vertical hanger rod 39 which is pivotally hung at 40 from the forwardly projecting upper end 41 of the standard 15. The rear end of the yoke lever 37 is pivoted at 42 to the upper end of a rod 43, and the lower end of this rod 43 is pivoted at 44 to the upper end of the shank 26 of the lower spindle carrier 26, 27. The front end of the yoke lever 37 is connectable with and disconnectable from the drill raising and lowering sleeve 19 by means of a coupling device 45.

When the yoke lever 37 is connected to the sleeve 19, descent of this sleeve 19 to feed the upper drill 23 into the work-piece 46, will swing the front end of said lever 37 downwardly, thereby upwardly swinging the rear end of said lever 37 and pulling upon the rod 43 to lift the carrier 26, 27, thus lifting the lower spindle 29 and feeding the lower drill 32 into said work-piece, the feeding of the two drills being at uniform speed.

Before the two drills can meet, the coupling device 45 is raised and the swinging movement of the yoke lever 37 is reversed by means yet to be described. Thus, upward feeding of the lower drill 32 stops and this drill 32 is lowered out of the way of the upper drill 23 which then completes the hole.

As the work of the lower drill stops slightly before that of the upper drill, the elements are preferably so related that said lower drill starts to cut slightly ahead of said upper drill, thus equalizing the work performed by the two drills and giving them equal life. The diagrammatic views (Figures 8 to 11) illustrate the actions of the two drills. In Figure 8, the lower drill 32 is ready to cut and the upper drill is still slightly spaced from the work-piece 46. In Figure 9, the drills have almost met but the feed of the lower drill 32 has stopped. In Figure 10, the lower drill 32 is descending away from the upper drill 23 as the latter completes the hole, and hole completion by said upper drill 23 is shown in Figure 11.

The construction of the coupling device and the means for lowering the lower drill upon release of said coupling device, are shown more particularly in Figures 3 to 6 although a number of the elements are seen on a small scale in Figures 1 and 2. A cap-like casing 47 receives the upper end of the sleeve 19 and is formed with a central opening 48 through which the spindle 18 extends slidably. Opposite sides of this casing are formed with outwardly projecting bearing bosses 49 and with aligned openings 50 extending through said bosses 49. The front extremities of the yoke lever furcations 51 have bearings 52 turnably mounted on the bosses 49, and two coupling dogs 53 extend slidably and non-rotatably through the openings 50 which extend through said bosses. The sleeve 19 is provided with downwardly facing lateral shoulders 54 which rest upon the inner ends of the dogs 53 when the sleeve 19 occupies its raised position and during lowering of this sleeve for drill feeding (see Figure 3). The dogs 53 thus connect the casing 47 with the sleeve 19 and cause the descent of the latter to swing the yoke lever 37 in the proper direction to raise the lower drill 32. At the proper moment, however, the dogs 53 are released from the shoulders 54 (Figure 5), allowing the sleeve 19 and upper spindle 18 to further descend without further raising the lower drill by further moving the casing 47 downwardly. To effect this dog release, the construction now to be described, is provided.

Two collars 55 are turnable upon the outer ends of the dogs 53 and are connected at 56 with the bearings 52 to turn with these bearings as the yoke lever 37 swings. These collars have inward projections 57 (preferably screws) and the collar-contained portions of the dogs 53 have cam grooves 58 receiving said projections 57. Thus, as the yoke lever 37 is swung by downward feeding of the sleeve 19, the bearings 52 turn upon the bosses 49 as shown by the arrows 59 and 60 in Figure 4, and through the connections 56, said bearings 52 turn the collars 55. This causes such coaction of the projections 57 and cam grooves 58 as to release the dogs 53 from the shoulders 54, allowing further descent of sleeve 19 and spindle 18 without further ascent of the lower spindle 32.

The connections 56 embody springs 61 which urge the collars 55 inwardly toward the casing 47, and said collars 55 are provided with set screws 62 for limiting their movement under the influence of said springs 61. By adjusting these set screws 62 and thus effecting endwise adjustment of the dogs 53 with respect to the shoulders 54, the moment of dog release may be varied as required.

Means is provided for positively lowering the lower drill 32 out of the way of the upper drill 23, as soon as the feed of said lower drill is stopped (by release of the dogs 53). This means is shown more particularly in Figures 4 to 6 although it appears on a small scale in Figures 1 and 2 also.

Two vertical hanger rods 63 are secured at 64 (Figures 1 and 2) to the bearing 17 of the standard 15, and the lower portions of said hanger rods extend slidably through openings 65 in the casing 47 of the coupling device 45. Two casing lifting levers 66 are slidably fulcrumed to the lower ends of the rods 63 by means of pins 67 carried by said rods and extending through longitudinal slots 68 in said levers. The pins 67 may have rollers if desired. The levers 66 are disposed radially of the sleeve 19 and the inner ends of said levers are pivoted to said sleeve as shown at 69. The casing 47 is provided with shoes preferably in the form of rollers 70 carried by arms 71 projecting downwardly from said casing, and said rollers are so located as to contact with the upper edges of the levers 66 upon predetermined lowering of the sleeve 19. When this sleeve 19 occupies its raised position (Figures 2 and 4) the levers 66 decline outwardly and the rollers 70 are upwardly spaced considerably from said levers. As the sleeve 19 is lowered to feed both drills into the work-piece, the casing 47 and its rollers 70 descend with said sleeve and the levers 66 so swing about their fulcrums that the outer ends of said levers rise. At the time the dogs 53 are released to stop the feed of the lower drill 32, the levers 66 and rollers 70 are in contact as best shown in Figure 6. Consequently, as the sleeve 19 is further lowered to cause the upper drill 23 to complete the hole, the levers 66 continue to swing, with the result that they lift the casing 47, thus swinging the yoke lever 37 in the reverse direction to lower the carrier 26, 27 and the drill 32. As the casing 47 rises, the dogs 53 again slide inwardly to the positions of Figure 3 but the shoulders 54 are then below said dogs due to the lowered position of the sleeve 19. When this sleeve 19 is again raised, upon completion of the drilling operation, the shoulders 54 engage the beveled inner ends 72 of the dogs 53, thus pushing said dogs outwardly against the action of the springs 61 and allowing said shoulders to pass said dogs. As soon as the shoulders clear the dogs, the springs 61 cause inward projection of said dogs under said shoulders, thus placing the elements in condition for the next drilling operation.

While the operation of the improved press may be clear from explanations given during description, it may be well to briefly describe it as follows:

As the sleeve 19 is lowered to feed the upper drill 23 into work-piece 46, the coupling device 45 swings the yoke lever 37 and thus effects raising of the lower drill carrier 26, 27 to feed the lower drill 32 into said workpiece. Before the two drills can meet, the coupling device 45 is released, stopping the feeding of the lower drill 32. As the sleeve 19 continues downwardly to cause the upper drill 23 to complete the hole, the levers 66 restore the coupling device 45 to raised position, thereby rocking the yoke lever 37 in the reverse direction to lower the lower drill 32. When the sleeve 19 is again raised at the completion of the drilling operation, the coupling device 45 again connects this sleeve with the yoke lever 37, placing the press in condition for the next drilling operation.

Suitable adjustments may be provided where advisable. The rod 43 is shown as formed from two sections adjustably connected by a turnbuckle 43 and a corresponding construction for the rods 39 and 63, including the turnbuckles 39 and 63. A chip guard and coolant deflector 73 may be provided above the bearing 28, and a coolant and chip receiving casing 74 is shown in dotted lines in Figure 2.

From the above detailed description of the invention, it is believed that the construction, use, and operation thereof will at once be apparent, and while there is herein shown and described the preferred embodiment of the invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What is claimed as new is:

1. A drill press comprising a table, an upper spindle over said table, means mounting said upper spindle for vertical movement, means for vertically moving said upper spindle, a lower spindle aligned with said upper spindle and disposed under said table, a carrier upon which said lower spindle is mounted, means mounting said carrier for vertical movement, means for rotating the upper spindle, a flexible drive connection between the upper end of the upper spindle and the lower end of the lower spindle for rotating them at the same speed, carrier operating means operatively connecting said upper spindle with said carrier and operative to raise said carrier as said upper spindle is lowered, said carrier operating means including releasable means for disconnecting said carrier operating means from said upper spindle, means for automatically releasing said releasable means when said carrier has been raised to a predetermined extent, and means for lowering said carrier upon release of said releasable means.

2. A drill press comprising a table, an upper spindle over said table, means mounting said upper spindle for vertical movement, means for vertically moving said upper spindle, a lower spindle aligned with said upper spindle and disposed under said table, a carrier upon which said lower spindle is mounted, means mounting said carrier for vertical movement, means for rotating the upper spindle, a flexible drive connection between the upper end of the upper spindle and the lower end of the lower spindle for rotating them at the same speed, carrier operating means operatively connecting said upper spindle with said carrier and operative to raise said carrier as said upper spindle is lowered, said carrier operating means including releasable means for disconnecting said carrier operating means from said upper spindle, means for automatically releasing said releasable means when said carrier has been raised to a predetermined extent, and means actuated by further descent of said upper spindle for lowering said carrier upon release of said releasable means.

3. A structure as specified in claim 1; said releasable means being constructed to automatically reconnect said carrier operating means with said upper spindle upon return of the latter to raised position.

4. A structure as specified in claim 2; said releasable means being constructed to automatically reconnect said carrier operating means with said upper spindle upon return of the latter to raised position.

5. A drill press comprising a table, an upper spindle over said table, means mounting said upper spindle for vertical movement, means for vertically moving said upper spindle, including a sleeve surrounding said upper spindle and movable vertically therewith, a lower spindle aligned with said upper spindle and disposed under said table, a carrier upon which said lower spindle is mounted, means mounting said carrier for vertical movement, means for rotating the upper spindle, a flexible drive connection between the upper end of the upper spindle and the lower end of the lower spindle for rotating them at the same speed, carrier operating means operatively connecting said sleeve with said carrier and operative to raise said carrier as said sleeve is lowered, said carrier operating means including releasable means for disconnecting said carrier operating means from said sleeve and means for automatically releasing said releasable means when said carrier has been raised to a predetermined extent, and means for lowering said carrier upon release of said releasable means.

6. A structure as specified in claim 5; said releasable means being constructed to automatically reconnect said carrier operating means with said sleeve upon return of said sleeve to raised position.

7. A structure as specified in claim 1; said carrier operating means including a vertically swingable lever fulcrumed between its ends and a rod connecting one end of said lever with said carrier, said releasable means being positioned to connect the other end of said lever with said sleeve.

8. A structure as specified in claim 5; said carrier operating means including a vertically swingable lever fulcrumed between its ends and a rod connecting one end of said levers with said carrier, said releasable means being positioned to connect the other end of said lever with said sleeve.

9. A drill press comprising a table, an upper spindle over said table, means mounting said upper spindle for vertical movement, means for vertically moving said upper spindle, including a sleeve surrounding said upper spindle and movable vertically therewith, a lower spindle aligned with said upper spindle and disposed under said table, a carrier upon which said lower spindle is mounted, means mounting said carrier for vertical movement, a coupling body adjacent the aforesaid sleeve, a coupling dog mounted on said body, said sleeve having a shoulder cooperable with said dog to connect said body with said sleeve for downward movement with the latter, a lever mounted adjacent said body, pivot means connecting one end of said lever with said body, whereby descent of said sleeve and body will swing said lever in one direction, connecting means from said lever to said carrier for raising the latter as said lever is swung as aforesaid, additional connecting means from said one end of said lever to said dog for releasing the latter when said lever has been swung to a predetermined extent, and means for lowering said carrier upon release of said dog.

10. A structure as specified in claim 9; said dog being constructed to re-engage said sleeve when the latter is returned to raised position.

11. A structure as specified in claim 9; said dog being slidably and non-rotatably mounted on said coupling body and disposed radially of said sleeve, said additional connecting means for releasing said dog comprising a cam on said dog and means engaging said cam and operated by said swinging of said lever.

12. A structure as specified in claim 9; said dog being slidably and non-rotatably mounted on said body concentric with said pivot means, said connecting means for releasing said dog comprising a collar turnably surrounding the outer end of said dog and connected with the pivoted end of said lever to be turned by the latter, an internal projection on said collar and a cam groove in said outer end of said dog, said cam groove receiving said projectron.

13. A structure as specified in claim 9; said dog being slidably and non-rotatably mounted on said body concentric with said pivot means, said connecting means for releasing said dog comprising a collar turnably surrounding the outer end of said dog and connected with the pivoted end of said lever to be turned by the latter, an internal projection on said collar and a cam groove in said outer end of said dog, said cam groove receiving said projection, said dog having a beveled inner end to reengage the aforesaid shoulder of said sleeve when the latter is again raised, the connecting means between said collar and lever including spring means allowing outward yielding of said dog when said shoulder engages said beveled end.

14. In a means for raising a lower drill spindle when an upper spindle-operating sleeve is moved downwardly; a coupling body adjacent said sleeve and having an external bearing boss disposed radially of said sleeve, a dog extending slidably and non-rotatably through said boss, said sleeve having a shoulder normally resting on the inner end of said dog, a lever having a bearing surrounding said boss and turnable thereon as said sleeve lowers and swings said lever, a collar turnably surrounding the outer end of said dog, means connecting said collar with said bearing to cause turning of said collar with said bear ing, and an internal projection on said collar, said outer end of said dog having a cam groove receiving said projection to retract said dog from said shoulder when said collar has been turned to a predetermined extent.

15. A structure as specified in claim 14; said collar and bearing connecting means including a spring urging said collar toward said bearing, and a set screw for limiting the movement of the collar under the influence of said spring.

16. In a drill press having an upper spindle, a sleeve surrounding said spindle for raising and lowering the same, a lower spindle, a vertically movable carrier for said lower spindle, and means for raising said carrier as said sleeve is lowered, said carrier raising means including a coupling body adjacent said sleeve and releasable means for connecting said coupling body with said sleeve while the latter is moving downwardly to a predetermined extent; a lever under said coupling body and extending radially from said sleeve, a fixed fulcrum with which said lever is slidably engaged between its ends to eflect upward swinging of the outer end of said lever as said sleeve descends, and a shoe on said coupling body to contact with the upper edge of said outer lever and when said sleeve has descended to the extent at which said releasable means is released, whereby further descent of said ilegve will cause said lever to again raise said coupling 17. A structure as specified in claim 16; together with a fixed vertical hanger carrying said fulcrum, said coupling body being slidably engaged with said hanger.

References Cited in the file of this patent UNITED STATES PATENTS 1,575,308 Alger et a1. Mar. 2, 1926 

